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Super Gross (polluter) Smog

J

jrowell

NAXJA Forum User
Location
Bakersfield
Failed smog today in a big way! Nox was WAY high.
ebe3ypyr.jpg
 
ARRRRGGGG!!!
Here's the info:
87 4.0. 35's with 4.88's.
Nothing major changed since the last smog... Fuel tank is all I think.
Cat doesn't have 5000 miles on it. This is mainly a trail rig, that get's trailered. I drive it to work every couple weeks. exhaust does have a weird odor. Temp runs 190 at the thermostat and 210 at the back of the head Unless I'm climbing a grade and it will jump to 220+ on both). New Bosch exhaust sensor a couple years ago.

Runs good... Seems to not have very good top end power and gets very bad MPG's (less than 10 I think)

Where to begin looking?
 
When was the last time you tested/replaced your o2 sensor?
 
I've read through a TON of High NOx Renix pages. My eyes are starting to gloss! I have not came across one that had nearly as high NOx readings as I had.
A couple of reoccurring causes:
High combustions temps - Bad O2 sensor - Bad EGR - Clogged injectors.

Can a bad EGR throw out the EXTREME NOx numbers?

Will High combustion temps show in the water temps?

Can an Bosch O2 sensor crap out in 2-3 years?

Will a bad O2 sensor cause bad MPG's and a bad exhaust odor?
 
Renii (plural of renix) that show high NOx are almost always running lean, which may or may not show in the water temp (usually it doesn't).

Cleaning the EGR system is a good start, usually if your O2 is bad, it makes it richer.

Try either some marvel mystery oil or seafoam in the gas tank and drive it around for a bit to clean the injector system. Also, while you're at it, clean the throttle body and intake manifold with seafoam.

Looking at your HC and CO numbers your cat is working just fine, however it looks like your mix is much leaner than it should be.

Also, could you explain the "strange odor" my jeep makes all kinds of strange odors, everything from burning oil to skunk, farts and burning electrical odors. Is it gas? Burning metal? In the latter case, I would say this is your cat/exhaust being extra hot.
 
Your o2 sensor could definitely be bad at 2-3 years. They can be bad out of the box, too. Not only could it be bad out of the box or at 2-3 years, but it would cause poor fuel economy and emissions, too. I was just reading a renix smog thread where the fix was an NTK oxygen sensor.
 
The strange odor is difficult to explain. Not gas or burning oil or electrical. Maybe closer to sulfur or light a match smell. Not really strong, just enough to make u think something is wrong.
 
Sulfur / rotten eggs smell in exhaust is unburnt fuel additives. If the ignition is working properly, it's probably the cat. It's supposed to re-burn everything that makes it out of the header - eggs smell included.
 
Plugs? Wires? Cap'n'Rotor?

Also, cleaning out the EGR system should be done (remove EGR valve, stick a chunk of wire down there and wiggle it around, spray in some chem-tool, repeat. When done, turn it over and blow the last of the goo you loosened up out)
 
Re: Re: Super Gross (polluter) Smog

BulletMaker said:
Plugs? Wires? Cap'n'Rotor?
Click to expand...

Maybe have 10-15 thousand miles on them. They look ok.
I'll clean the egr this weekend, but i just don't see the egr having that much effect. If i was a couple hundred or so off i think maybe... But I'm off by thousands.
Also, the cat is basically bran new. No dents in it. Hope that's not it, those suckers are expensive as hell now!
 
My EGR is inop. doesn't affect the sniffer.
 
Johnnie Walker said:
My EGR is inop. doesn't affect the sniffer.
Click to expand...

Ya, in reading the hundreds of High Nox threads, I've came across a couple that say bypassing it made the results better. Maybe it'll make a little difference either way, I just don't see it causing a 3000 nox number. Of course, that is my uneducated in smog equipment opinion. I could be totally wrong!
 
do cap/rotor/plug wires/air filter.

then sea foam the gas , oil and intake.

grab plugs/oil and filter/o2 sensor after sea foaming and throw those on.

Check for exhaust manifold leaks and cracks. Check for any exhaust leaks.
check for vacuum and intake leaks.

Adjust TPS properly.
Test the EGR too.
Test coolant temp sensor.
Possibly get all injectors cleaned locally.

It was good bowling with you in MOAB.


Make sure gas tank is totally full, and add a pint or two of acetone before smoking next time.

if it was some cheap crappy cat, it could be bad already too after 3 years, leave that for last.
 
Make sure you have Champton RCY9C plugs in, they're the right heat range. Check vacuum leaks, etc., anything that will make it run lean.

Make Cal bring his diagnostic tool next time he's up there and plug it in, get a live readout of all sensors.
 
blondejoncherokee said:
do cap/rotor/plug wires/air filter.

then sea foam the gas , oil and intake.

grab plugs/oil and filter/o2 sensor after sea foaming and throw those on.

Check for exhaust manifold leaks and cracks. Check for any exhaust leaks.
check for vacuum and intake leaks.

Adjust TPS properly.
Test the EGR too.
Test coolant temp sensor.
Possibly get all injectors cleaned locally.

It was good bowling with you in MOAB.


Make sure gas tank is totally full, and add a pint or two of acetone before smoking next time.

if it was some cheap crappy cat, it could be bad already too after 3 years, leave that for last.
Click to expand...
That was fun in Moab! Great how that venue worked out in the end.

The Injectors are something I have never changed on this rig. They could have 300,000 plus miles on them. The heep runs good (although lacks top end power & gets hot on grades) and idles good, so I figured they must be doing their job.

As I recall, the cat was upwards of $400. Some kind of federally (or state) mandated type.

Coolant temp sensor. The one in the back of the head works fine, but I don't believe that has any affect on Smog. Now the one down on the block is another matter. Not sure what that does really. Never messed with it.

I'm going to try and knock all this crap off this weekend.
 
GSequoia said:
Make sure you have Champton RCY9C plugs in, they're the right heat range. Check vacuum leaks, etc., anything that will make it run lean.

Make Cal bring his diagnostic tool next time he's up there and plug it in, get a live readout of all sensors.
Click to expand...

A diagnostic tool for my Renix? I din't know anyone had those anymore!
 
jrowell said:
A diagnostic tool for my Renix? I din't know anyone had those anymore!
Click to expand...

Cal has the Renault one, others have the Chrysler one (DRB-2), and I have the Snap On one (MT-2500).
 
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